1. Field of the Invention
The present invention relates to metallurgy, and more particularly, to means for teeming molten metal into various kinds of moulds.
The invention is applicable to machines for continuous casting of metal into molds. It may also find extensive use in non-ferrous metallurgy.
2. Description of the Prior Art
In practice, wide use is made of metal teeming means (or ladle) which comprise a teeming chamber connected with refractory-lined sleeves for discharging molten metal into moulds and provided with a system for regulating the level of metal therein. The system in question includes a level-sensing means installed in the mould and connected to electromagnetic means for regulating the flow rate at which the molten metal is discharged from the teeming chamber.
Such construction of the metal-level control system is disadvantageous in that the level-sensing means are directly exposed to the action of molten metal. This in turn renders the control system unreliable in operation and leads to erroneous measurements in the level of metal. Electromagnetic flow gauges are complicated in construction and unreliable in operation under high-temperature conditions, and require substantial power inputs and operational costs.
From the above it follows that the prior-art metal teeming means are complicated in construction and the level control devices incorporated therein are insufficiently reliable in operation.
The error in gauging the level of metal may be as high as 20 percent and more, which brings about overfilling of some moulds and underfilling of others and, in the final count, results in a high degree of defective products and frequent faults in the operation of equipment.
There is also known means for teeming steel into, and regulating its level in the mould of a continuous casting machine. The means in question comprises a stoppered ladle having an actuator associated with a Laser-operated means for gauging the level of metal in the mould. Needless to say that such a construction is rather complicated and expensive due to the use of the Laser technique and optical instrumentation, which require that strictly stable operating conditions be provided in a steelmaking shop. This is an extremely difficult task to perform. Thus it should be mentioned that because of insufficiently reliable operation of the metal gauging means, the rate of errors in gauging the level of metal in the mould increases to bring about faulty operation of the metal-level control means. A higher amount of errors in adjusting the level of metal in the mould is caused by a time delay in cooperation between the metal-level gauging system and the actuator of the ladle stoppered mechanism. This also may result in the overfilling of the mould and, consequently, in damage to the equipment.